Disengaging a motor on a spring powered hurdler

[Peter Matteson]

Originally Posted by Kevin Sevcik

See, we too were thinking along these lines last year. The problem is that any of these mechanisms that we found would lock under load whether by design or lack thereof. To the former, I'm absolutely certain that the freewheel on an auto winch is designed to lock under load. Or, at the very least, be very difficult to release under load. Imagine the consequences if you could easily bump the freewheel while using the winch to lift/tow/pull something.

This can be fixed by "re-working" the mechanism. We made a compact shoulder out of a modified winch in 2005 and never had a problem once we worked it over. It cost us $70 and we had to machine 2 parts (motor mount and input shaft) to get it to work. It's a cheap solution that you can make work with minimal effort if look around.

[chapmatr]

We were thinking of using a gear with teeth missing to pull it back, although that would require a non-winchy device.

[GUI]

Why not mount a winch so it can spin freely, then use dog gears to engage/disengage it?

I like your idea about the shifters. Andymark makes planetary gearboxes that changes the output of a Fisher-Price motor into that of a CIM. Two FP's Into that, into a Gen2 with one of the speeds taken off should be plenty of force to compress a decent spring, assuming a post gearbox reduction. It all comes pre-made, takes little modification, and is actually quite light.